In an attempt to identify and evaluate chemotherapeutic agents that would be efficacious in the treatment of carcinoma of the prostate, the National Prostatic Cancer Project (NPCP) established the Cooperative Clinical Trials Program for the development and implementation of chemotherapy protocols for advanced stages of the disease. This endeavor was predicted in early observations that carcinoma of the prostate represents a heterogeneous entity with some patient groups responding to hormonal manipulation for a variable period of time. Controlled studies were established at the inception of the NPCP in 1973 whereupon several cytotoxic agents were tried clinically, either singly or in combination. The results of these clinical trials have been published. Trials are currently under way in establishing optimum adjuvant therapy for patients undergoing definitive extirpative surgery and/or radiotherapy.